#include<stdio.h>
#include<string.h>
#include<stdlib.h>

#define USER "USER"
int main(){
  char* who = getenv(USER);
  //实现一个只有root能执行的指令
  if(strcmp(who,"root")==0){
    
  printf("user:%s\n",who);
  printf("user:%s\n",who);
  printf("user:%s\n",who);

  }else{
    printf("权限不够\n");
  }

  

  return 0;
}
